Turbine vane rings form portions of a turbine gaspath, sometimes by linking turbine rotors together. Turbine vane rings are often preferred to vane segments for their simplicity. Turbine vane rings are composed of an outer and an inner ring, often referred to as shrouds, which are connected together with the airfoil vanes.
Some engine operating conditions can create hot spots in the gaspath. These hotspots will unevenly heat the airfoil vanes generating localized high stresses where the peak temperatures and the stress raisers are localized. Stress raisers may consist of an array of slots that are used to pass engine instrumentations to monitor engine gaspath temperature or the provisions of narrow slots or key hole slots or T-shape slots in the rails of the turbine vane ring. To reduce leakage, thin metal plate seals may be placed in a transverse slot to close off the stress raiser openings.